In the construction of commercial and industrial buildings of the type which has concrete wall panels formed by using the tilt-slab method, a concrete building floor is normally poured in place and is then coated with a release agent to form a horizontal forming surface for the wall panels. The forms for producing the concrete wall panels are then placed on the forming surface, and reinforcing steel or rebars are positioned within the forms. When concrete is poured within the forms, the top edges of the forms are used as a guide for a screed which forms the top surface of the wall panels. After the concrete wall panels are cured, they are lifted or tilted to vertical positions to form the outer walls of the building.
The forms include bulkheads which separate and define the adjacent concrete wall panels poured onto the forming surface, and the bulkheads are usually constructed of solid wood boards. When it is desired to form chamfer corners on the outer and/or inner surfaces of the concrete wall panels to avoid chipping of the concrete at the corners of the wall panels and/or for receiving a joint caulking or other gap filling material, triangular strips of wood are commonly glued or attached to edge portions of the wood bulkhead boards. The bulkhead boards and strips are then treated or sprayed with a concrete release agent. However, it is not uncommon for the wood bulkhead boards and attached chamfer forming strips to be destroyed or damaged when the cured concrete wall panels are separated and tilted to vertical positions. As a result, the bulkhead forming boards and chamfer forming strips cannot be reused.
It is known to extrude a chamfer forming strip of a semi-rigid plastics material such as polyvinylchloride (PVC) and with a generally uniform wall thickness. The extruded strip includes a slightly arcuate bottom wall which integrally connects upwardly and inwardly projecting side walls having chamfer forming outer surfaces. The upper edges of the inclined chamfer forming walls engage opposite side surfaces of a bulkhead forming board which is held in a vertical position by fasteners or nails at opposite ends of the board. The chamfer forming extrusion eliminates the need for attaching the triangular chamfer forming wood strips to the edge portions of the wood bulkhead boards.
The present invention is directed to an improved bulkhead device for separating adjacent concrete wall panels poured onto a concrete floor or other forming surface and which provides the desirable advantages of durability, reusability and economy of construction in addition to providing a high quality joint between the concrete panels. The bulkhead device of the invention may also be cut to desired lengths with conventional cutting tools and minimizes the use of fasteners such and screws and nails, and requires no special coating or concrete release agent on the device.
In accordance with a preferred embodiment of the invention, a bulkhead device includes an elongated base member or channel of extruded semi-rigid plastics material and which is adapted to be secured by screws to a concrete floor or other forming surface. The base channel has upwardly projecting side walls with inwardly projecting and longitudinally extending opposing teeth. The teeth releasably engage outwardly projecting teeth on the lower portion of space side walls of a generally U-shaped bulkhead member of extruded semi-rigid plastics material. The space side walls of the bulkhead member have opposing inner ribs or teeth for gripping a bulkhead extension member or board. Inclined walls project outwardly and downwardly from the side walls of the bulkhead member and have lower tapered edge portions for engaging the forming surface to form chamfer corners on the concrete panels.
Other features and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.